Correlation Effects on Atom Density Profiles of 1-D and 2-D Polarized Atomic-Fermi-Gas Loaded on Optical Lattice

TL;DR

This paper explores how optical lattice potentials influence atom density profiles in polarized 1D and 2D Fermi gases, revealing that population imbalance tends to stay in the core region, differing from non-lattice cases.

Contribution

It provides a detailed numerical analysis of population imbalance effects on atom density profiles in optical lattices using exact diagonalization and DMRG methods.

Findings

Population imbalance remains in the core region with optical lattices.

Phase separation occurs but differs from non-lattice systems.

Effective models explain the numerical results in strong attraction regimes.

Abstract

We investigate effects of optical lattice potential in one- and two-dimensional two-component trapped Fermi gases with population imbalances. Using the exact diagonalization and the density matrix renormalization group methods complementarily, we calculate the atom density profile from the ground state many-body wavefunction as a function of attractive interaction strength for various population imbalances. The numerical results reveal that although a phase separation between the superfluid core and the shell cloud of excess atoms occurs as observed in experiments without the optical lattice, the population imbalance generally remains in the core region in contrast to the non-lattice cases. The essence of the numerical results in a strong attractive regime can be explained by an effective model composed of Cooper pairs and excess major fermions.